A common type of portable oxygen apparatus is disclosed in U.S. Pat. No. 2,831,607 and comprises an automatic pressure regulator which is mounted on the outlet valve of an oxygen tank and is adapted to provide oxygen to a patient.
As shown in such patent, the automatic pressure regulator comprises a body which has a pair of chambers each having an orifice associated therewith with one chamber communicating with the other and a diaphragm associated with each orifice to control the pressure of oxygen in each chamber. The oxygen passes in the first chamber and thereafter into the second chamber before passing to the patient.
Such an inhalation apparatus has proved quite successful in providing oxygen as required.
As disclosed in U.S. Pat. No. 2,831,607, it is desirable to provide for a safety escape for the gas and as disclosed in that patent, a safety valve is associated with the diaphragm in the second chamber.
Among the objectives of the present invention are to provide a safety relief that is reliable and will continue to provide oxygen to the patient even if the pressure exceeds a predetermined amount. Furthermore in accordance with the invention, the automatic regulator provides a predetermined amount of oxygen. Among the furter objectives of the present invention are to provide an inhalation apparatus which can be more readily serviced.